Bria-IMT Regimen Exceeds Survival Data of SOC in Metastatic Breast Cancer

The 4 patients who remain on follow-up have an observed OS of 14, 15, 24, and 25 months, respectively.

Bria-IMT in combination with immune checkpoint inhibitor therapy exceeded the survival data of current standard of care for patients with metastatic breast cancer, according to a news release from the developer, BriaCell.¹

Data from the phase 2 trial (NCT03328026) evaluating Bria-IMT in patients with metastatic breast cancer show a 1-year survival rate of 55%, with 4 of 13 patients recruited in 2022 remaining in survival follow-up; the same regimen is being evaluated as part of the phase 3 BRIA-ABC trial (NCT06072612).²

Additionally, among a patient group undergoing treatment since 2022, the median overall survival (OS) reported with the Bria-IMT combination was 15.6 months. Median OS for comparable patient groups reported in prior literature ranged from 6.9 to 9.8 months. The median OS among patients treated since 2022 is an improvement from 13.4 months reported in survival findings presented in December 2023.

Furthermore, among the same patient group who underwent treatment in 2022, the median progression-free survival (PFS) with the combination therapy was 4.1 months, up from 3.9 months reported in December 2023.

The 4 patients who remain on follow-up have an observed OS of 14, 15, 24, and 25 months, respectively. Within this group, 2 patients received 8 cycles of therapy, 1 received 13 cycles, and another received 19 cycles. One patient is still undergoing treatment with the Bria-IMT regimen as part of the phase 2 trial.

“With over 40,000 deaths each year in the [United States] alone, late-stage [metastatic breast cancer] remains an important unmet medical need for many patients and their families. Approved treatments are restricted by poor survival and harsh [adverse] effects,” Adam M. Brufsky, MD, PhD, FACP, a professor of Medicine at the University of Pittsburgh School of Medicine and medical director of the Magee-Women's Cancer Program, said in the news release on the study findings.¹ “We are impressed with BriaCell’s promising randomized phase 2 survival data indicating robust survival and a preferred tolerability profile for Bria-IMT and look forward to seeing the data being replicated in BriaCell’s pivotal phase 3 study.”

Phase 2 study investigators enrolled 54 heavily pre-treated patients with metastatic breast cancer to receive Bria-IMT in combination with immune checkpoint inhibitors, 37 of whom were treated with the regimen currently being used in the phase 3 study. The median number of prior treatments was 6 within this patient population. Final median OS is pending, as multiple patients are alive.

Study treatment included the Bria-IMT regimen, consisting of intradermal inoculation at 4 sites, with 375 mg of intravenous retifanlimab (Zynyz) given once every 3 weeks.³ Patients were pre-treated with low-dose cyclophosphamide 2 to 3 days prior to initial therapy dosing and were given post-inoculation interferon at low doses approximately 2 days following treatment.

The trial’s primary end points were safety as assessed by adverse effects (AEs), serious AEs, the proportion of patients with safety laboratory parameter abnormalities, and QT interval. Secondary end points included objective response rate, non-progressive rate, and duration of response.

“Significant numbers of patients with metastatic breast cancer do not respond to currently approved drugs, including checkpoint inhibitors [CPIs] and antibody drug conjugates [ADCs], and have a very limited lifespan of weeks to a few months,” William V. Williams, MD, FACP, president and chief executive officer of BriaCell, said in the news release.1 “BriaCell’s clinical data supports our hypothesis that our regimen has prolonged survival in patients with metastatic breast cancer who otherwise have not responded to currently available treatments. We look forward to further confirming these impressive data in our ongoing pivotal phase 3 study, with interim results expected in the second half of 2025.”

References

1. BriaCell reports outperforming metastatic breast cancer patients and standard-beating survival data. BriaCell Therapeutics Corp. October 22, 2024. Accessed October 23, 2024. https://tinyurl.com/5n95z5ww
2. BriaCell reports positive overall survival (OS) in metastatic breast cancer. News release. BriaCell Therapeutics Corp. September 11, 2024. Accessed October 23, 2024. https://tinyurl.com/5n8v7ayd
3. Combination study of SV-BR-1-GM with retifanlimab. ClinicalTrials.gov. Updated October 6, 2023. Accessed October 23, 2024. https://tinyurl.com/mr38fdwn